Tracing device



June 23, 1931. GASTELL 1,811,121

TRACING DEVICE Filed March 26. 1929 [N V EN TOR.

m A TTORN E YS.

Patented June 23, 1931 n 1,811,121,

UNITED STATES PATENT OFFICE, y

Application filed March 26, 1929, Serial No; 350,071, and in Germany May 9, 1928.

The subject of the present invention is a board, thearms are moved towards one an-' tracing device which enables points, lines or other in such a manner that the drawing penoutlines from one sideof work pieces, such as oil with its point bears against the invisible, planks, boards and plates, to be transferred for example the under surface of the mate- '3 to the opposite side, and which may be parrial, and the metal pin on the visible, for exticularly useful when marking the fauity ample upper surface of the material. If now places in the material on one side on the opthe entire instrument is moved in a direction posite side exactly in position and correct in parallel to the surface of the board in such a shape, the outlines of the faulty places bemanner that the point of the metal pin is 10 coming visible on theside on which the outpassed along the faulty places on the visible lin ar to b drawn, side of the board the drawing pencil draws When it isdesired that both sides of the in an entirely accurate position on the repiece which has been cut out are to be free versed side the contours of the faulty places from faults, for example the holes of traversed by the metal pin.

branches or cracks which pass at an angle to Various examples of construction in acthe opposite side, faulty places must not only cordance with the invention are illustrated be avoided on the side on which the outlines in the accompanying drawings, wherein of the piece to be cutout are drawn but also Fl res l to 4 show one form of construcon the oppositely disposed side. In order to tion in which the twoarms are pivotally con 7 120 d r this possible, the faulty places of the nected together in the manner of tongs and surface opposite the one on which the outcan be manually moved towards one another lines of the pieces to be cut out must be indiby compressing the other ends of th r cated on the tracing surface in their correct WhIChare extended beyond the pivoted osition points and formed as handles. Figure 5 is The tracing device according to the present an elevational View partly in section of a invention, which is adapted to be preferably d fication. v manipulated freely by hand, enables this In the drawings 1 and 2 indicate the two transfer to be effected in an extremely simarms which are pivoted together at 3 and ple, convenient and accurate manner. It at 4 are formed into handles which are prefer- 30 substantially consists of two rigid, preferably ably covered with coverings of soft material, 8

parallel arms, preferably of equal length, for example leather or rubber. At the oppomovably connected together at their one end Sitely disposed end of the arm 1 there are at right angles to one another, or hinged formed extensions, for example in the form movably, for example in the manner of tongs, of a fork, of which the arms 5 are located 35 between which arms the Work piece to be in a plane parallel t0 the main arm and at 35 t t d may h fitt d. right angles to the plane of connection. Each of these arms carries'at the end, at These engage the surface being marked to exactly the same distance from the point of prevent tilting and to maintain the common connection of the arms,'at right angles to its axis of the pin 6' and the drawing pencil 7 40 longitudinal direction, a preferably pointed accurately at right angles to the drawing pin which is movable in its longitudinal disurface of the work piece even when the derections. At least one of the pins is a drawvice is being moved. ing orcoloured pencil, whilst the one above is The pin 6 is adjustable in its longitudinal preferably made of metal. Both pins are so direction, for example by means of a screw :4 arranged that when their points are in conthread and is adjustable in any suitable posis tact with the surfaces on both sides of the tion, for example by means of the lock nut 8 work piece, their central axles are disposed or a lateral set screw in the guide bush 28, in a straight line. After the device has been the guide bush being preferably located fitted with its two arms on the opposite sides above the fork shaped bearing and support- M 9 of the work piece, for example a wooden ing members 5, 5 and is connected thereto by the arcuate supporting arms 9, 10 and 11 which are directed upwardly towards one another.

At the opposite end of the other main arm 2 is provided a guide bush 12. In this is slidably mounted a guide sleeve 13 which can be locked in any desired. position. by a set screw Ll. Into the guide sleeve 13 is. fitted a drawing or writing pencil? of which, the adjustment is effected by means of a rod 16 slidably mounted in the sleeve and adapted to be locked in any suitable position. by. a set screw 15.

At its outer end. the rod.16.is preferably provided with a head 17 and at its inner end withanlenlargementz in order to prevent it: from falling out Oftllfi bottonrof the open.- ing inthesleeve 13; All: these parts are so arranged; that their. central: axis coincides witlrthat of: the pin 6 whenthe arms of. the tongs. have been approached towards one another to such aniextent that the pins bear against: the oppositely disposed surfaces. of the work piece.

In. order-to enable the pencil; to. bearresiliently. against the surface to be drawn upon,.the drawing pencil; may be subjected to the actionof; a spring, for example-insuch a manner that between it'andLtherodforming alower. support: thereforthere is located in the sleeve 13 a spiral spring 26 (see Figure 5). 'lhe sleeue l3.is.preferably provided: on the outside witha scale-by meansof' which it is possible -to effects preliminary substantially accurate adjustment; of the distance between the drawing -pencil andithe pin 6in accordance withtheknown thickness of. the boardfor. exampleeby a device actuated by lever mechanism orby pulling mechanism from the handle,- or inany other suitable manner,

or for; example in. such a manner. that: the sleeve, which directly, carries the. drawing pencil, is itself withdrawn into the guide bush by meansof such adevice, .inwhich case thissleeve. is slidably mounted inthe sleeve 13 and. is resiliently. mountedzin relation thereto, for example by interposing. aspiral spring betweenthe collar provided atthe upper end of the inner; sleeve and the upper edge of; the sleeve 12..

F or. limiting the movementof the arms the handles a. of the tongs are preferably connected' together by connecting members 18 ofplianti material, fOTyGXQHIPlG leather, of which :the length corresponds with .the maximum distance between the handles 4:. By interposing a spring 18 between the two handles, it is possible, according to Figure 4, to obtain an automatic opening of the tongs when the pressure by hand of the handles is removed. I

Instead of pivoting together the arms of the device they may also. be connected so asoto be capable of moving parallel to one another for example in such a manner that one arm is at the end provided with a bolt extending at right angles thereto which can be moved in a corresponding guide bush providedjat the end,of-. the other arm and locked in any suitable position therein. Also in this case handlesanay. beprovided on one'or; both of the movable parts.

t. is also. possible instead of connecting members 6,, 9, l0 and 11,.whichform the supporting surface of one arm, rigidly t0-the arm. 1 to. apply these parts by means, ofa separate guide member-movable in. a guide bush; securedlto the arinlland if; desi'redl also under the action. ofa spring and capable of being adjusted in aqdefinite posit-ion, and-a similar assemblage may. also be rigidly mounted or movably mounted in. the manner. described; on the arm2 of. the device so that'if'. desired botharms may bear whilst being guided or under the acticnof springs against. the-two sides of the board;

With such a. spring actuated; arrangement ofa the parts. forming; the supporting surfacesthearmsl and2'offthe device may-also be connected together'rigidly. at theirpoint oficonnection according to Figured In this iigure- 1. and; 2. indicate the arms of the device which, at their outer ends are rigidly connected together and for example at 27 areprovided with; an intermediate member or corering in the form of! a handle. The metalzpiniiif pointed at its lowerendis again movably. mounted in thesleeve 20andjis-capable of; adjustment by means. of the set screw-2e. ThesleeveQOisconnected at its lower; end with thearcuate arms 5, 9, and 11 forming thesupporting surface in the manner describedin connection with-the previous. figures and; is slidably guided in a sleeve 21. which in turn is slidably mounted in the guide bush 22 securedgto the arm 1. A spiral. spring. 23 fitted; between the lower endzof the bush. 21; and a! collar; provided, at the lower end of; the bush 20 tends to-press the bushQO together: with the parts forming the supporting surface downwardly so. that the devicebears resiliently with this supporting surface on the surface ofthe material which is turned towards it;

The set; screwQ-fiserves to lock the; guide sleeve 21 in the desired-position in the guide bush 22. Also inthis case the armflxof-the device which supportsthe drawing pencil may. be providediwitlra springactnatedisup porting surface. When using the devicewith spring actuated supporting surfaces the adjustable parts of one arm or of both arms are first adjusted so as to bring the ends of the pins to an interval somewhat less than the thickness of the material to be operated upon, for example a board. It is then easily possible, by reason of the resilient yielding of one or both supporting surfaces to fit the device with its two arms over the work piece and then in the manner above described, after adj usting the pointed pin 6 almost in contact with the surface of the material, to traverse the incorrect points and to effect the tracing thereof on the other side of the board.

By the provision of longitudinal guides of known character, for example on the principle of groove and tongue, between the relatively movable parts, for example between the sleeve 20 and the sleeve 21, or these and the guide bush 22 or the sleeve 13 and the guide bush 12 and so forth a revolving of these parts can be prevented.

In a similar manner as in connection with boards and the like of wood, the device described can also be used for plates of other suitable material.

The term extension members, by means of which supporting surfaces are formed for preventing tilting of the device, is intended to include in the specification and the claims members which as such form a supporting surface and also those, for example curved members, which only define a surface.

I claim 1. In a hand operated freely movable transmission device for the purpose described, including in combination, two rigid arms having their inner portions arranged in crossed formation and pivotally connected to each other, handles on said inner portions, pins mounted on the free outer ends of both of said arms and extending toward each other and arranged in alignment with each other, a tilting preventing member for engaging the surface to be operated upon mounted on one of said arms, a guide member on the arm opposite the tilting preventing member, the pin on the arm carrying the guide member being in the form of a pencil, a sleeve for receiving said pencil and longitudinally adjustable in the guide member and provided with a scale, a spring mounted in the sleeve and bearing against the inner end of the pencil, and a tension regulating member acting on the spring and the pencil.

2. In a hand operated transmission device as claimed in claim 1, wherein the tilting preventing member is resiliently urged toward the other arm.

In testimony whereof I aflix my signature.

ALBERT GASTELL. 

